We have termites in our house. "Tenting" the house has been recommended to eliminate the termites. Do you have any recommendations or advice about using this technique? Are there long-term negative effects and possible health hazards?

A: Tenting a house to eliminate termites involves covering the whole building with a gas-tight tarp and then releasing a gas, usually an odorless, colorless product called Vikane. You have to remove all pets and plants from the house and put all food that you leave inside into special protective bags. The tarp usually is removed 12 to 24 hours after release of the gas; afterward, the house must be aired for at least six hours and then tested for any remaining traces of the gas. Practically speaking, tenting should kill all the termites, but it provides no protection against future infestations.

I don't recommend tenting. The fact that it is odorless and colorless doesn't mean that Vikane is harmless. It is extremely toxic. Exposure can depress the central nervous system and long-term exposure can lead to blood and bone problems.

Another termiticide, methyl bromide, is being phased out by the U.S. Environmental Protection Agency (EPA) to comply with Clean Air Act regulations. Methyl bromide depletes the earth's ozone layer.

There are a number of safer, alternatives to rid your house of termites although not all are widely available:

Heat: This method involves applying heat to infested walls or even the whole house. The heat (120 degrees Fahrenheit) destroys termites and their eggs. Freezing: Here, minus 350-degree liquid nitrogen is pumped through small holes drilled into infested wood. This gradually lowers the temperature of the wood to minus 20 degrees. Pest control operators use fiber optic technology to locate the termites in the wood so they know where to place the liquid nitrogen. Baiting: Designed to eliminate subterranean termites, a method called the Sentricon Colony Eliminating System uses baiting stations containing tiny amounts of a poison that affects only termites and is much easier on the environment than spraying methods. Termites pick up the poison bait and then spread it to other termites as they travel through the infested area. Fungal treatment: This innovation uses a fungus that is common (and beneficial) in soil but lethal to termites. To work it must be applied directly to termite galleries.Other new methods worth exploring include microwave treatments, electroshock (via a pulsating current that doesn't burn wood) and injection of oil made from orange peels into wood.